The present invention is applicable to any hearing aid of the type having at least a part of the hearing aid locatable within the ear canal. While not intended to be so limited, for purposes of an exemplary showing, the invention will be described in its application to that type of hearing aid which is most frequently encountered today, the hearing aid being a completely self-contained unit locatable within the ear and ear canal.
In recent years great improvement has been made in hearing aids due, among other things, to miniaturization Most hearing aids, today, are completely self-contained. In its most usual form a hearing aid comprises a hollow plastic body custom fitted to the ear and ear canal in which it is to be worn. Within the hearing aid body there is located an electronic sound amplification circuit including a speaker. The electronic circuit is powered by a battery such as an air-activated, zinc battery, well known in the art. Such batteries normally have a useful life of from about 15 to about 20 days. While such hearing aids are worn by people of all ages, the preponderance of hearing aid users are senior citizens.
A problem encountered with the use of such hearing aids is the accumulation of moisture in the ear canal. The moisture, in turn, leads to irritation of the ear canal. This moisture induced irritation can be sufficiently unpleasant as to cause hearing aid owners to decline to use them, or to use them only infrequently even in instances where their constant use would be beneficial. The present invention is based upon the discovery that the inclusion of a replaceable container of desiccant or drying agent within the hearing aid body, and the inclusion of at least one opening in the hearing aid body providing communication between the interior of the hearing aid body and the ear canal, will markedly reduce or eliminate this moisture induced irritation.
It will be understood that in order for the replaceable container of desiccant to fit within the hearing aid body, the desiccant container must be quite small, holding only a small amount of the drying agent. As a result, the desiccant container, like the battery, should be changed at regular intervals. While it is within the scope of the invention to have the desiccant container totally separate from the battery and the changing of the desiccant container a wholly separate step from changing the battery, this situation is not preferred. The hearing aid user is readily aware when the battery should be changed since the hearing aid does not function properly with a weak or dead battery. This is not the case, however, with respect to the desiccant which simply must be remembered if the recurrence of irritation is to be avoided. It is thus preferable that a battery and desiccant container be packaged together so that the hearing aid user is reminded to replace both. Even more preferred is a situation wherein the desiccant container is physically associated with the battery so that both are changed at the same time as a single unit in a single operation.